1. Field of the Invention
The present invention relates to an in-mould coating device, and more particularly to an in-mould coating device, which can form a coating film on the surface of a semi-finished product in mould by irradiating a liquid lacquer or other liquid coating materials injected into the mould.
2. Description of the Prior Art
A conventional in-mould coating method (disclosed in TW Patent Application No. 093135078) is heating liquid lacquer to harden it by use of heating wire or other heating methods to form a coating film on the surface of an injection molding semi-finished product. However, the above conventional method has the following disadvantages: it is required to additionally develop a thermosetting liquid lacquer and; it is likely to cause uneven control temperature and uneven hardening: when the heating wire or other heating methods is used, the liquid lacquer is heated to solidify via steel mould insert by heat conduction in such a manner that the coating film can be combined on the surface of the injection molding product.
Referring then to FIGS. 5 and 6, an optical fiber coating device 80 is shown, wherein the optical fiber 81 is placed in the molding cavity 82, and then photo-curing resin is fed through the feed-in pipe 83, meanwhile, UV light X passes through an interval 84 to harden the photo-curing resin. However, only the photo-curing resin close to the interval 84 can be hardened since the UV light can only reach the part of the molding cavity 82 close to the interval 84, therefore, the curing of the resin is nonuniform.
It needs to form a plurality of intervals 84 around the molding cavity 82 in order to have a uniform curing of the resin, however, the molding cavity 82 is used to receive photo-curing resin, so it will have the resin leakage problem if the intervals 84 are formed in the sidewall or below the molding cavity 82. Even if there is no resin leakage problem, too many intervals 84 will only make the light irradiation more uneven, so that the curing of the resin is still nonuniform.
Furthermore, even if the optical fiber 81 is used as a light source to introduce light directly into the cavity, however, it still cannot irradiate the photo-curing resin evenly due to the optical fiber 81 is a straight line, and if optical fiber 82 is arranged all over the molding cavity 82, there will be no space left for other necessary equipments.
Referring then to FIG. 7, another type of optical fiber coating device 90 is provided with a camera 92 to monitor the condition inside the molding cavity 91, however, the camera 92 can only monitor but is still unable to solve the problem of the nonuniform curing.
The present invention has arisen to mitigate and/or obviate the afore-mentioned disadvantages.